Water temperature key in finding active walleyes

Southern Wisconsin is experiencing dramatic environmental variables as we work through seasonal change this spring.

Warm-blooded creatures adapt quickly to 30-degree temperature swings and sharp changes in barometric pressure that occur every two or three days.

Cold-blooded creatures like fish don’t respond so quickly.

Ice is still covering many lakes in this part of the state. Even where water is open and flowing, cold night temperatures almost cancel warmth gained from the daytime April sun.

Fish sticks in a freezer at zero degrees or 25 degrees are still fish sticks in a freezer. When Mother Nature puts them in the ’frig, they will thaw out overnight. We’re still waiting for this day to come—and the winds of seasonal change to calm down.

Every river has small niches where those marble-eyed fish sticks have already been moved from freezer to ’frig. An accurate surface-temperature gauge is the best tool for locating fish trying to awaken from their frozen zombie state.

The ability to “read” a river comes into play even before checking changes in temperature status on the boat’s electronics. If your river-reading ability is just slightly north of the “see Spot run” level, and you have a temperature gauge in the boat, the odds of washing the landing net increase dramatically.

Any source of water entering the river’s grand flow can be a fish magnet. Creeks and other tributaries are obvious places to look for changes in temperature. Drain tubes and similar subtle structures can provide even more dramatic temperature changes.

Last week I was guiding on the Mississippi River. Water temperatures ranged from 33 down to 30 degrees on the main channel. A major running slough just off of the main channel had 34-degree water—still “deep freeze” status to cold-blooded walleyes.

This particular running slough has several smaller tributaries entering the water column. While easing the boat upstream towards this confluence, the numbers on my Lund’s surface-temperature gauge began to climb. Thirty-six degrees—39 degrees—FORTY DEGREES.

Electronic signatures on the main screen indicated fish species had also discovered this substantial temperature change. First there were a few little orange digital boomerangs, then dozens.

When the Humminbird 597 said the water temperature was 39 degrees over water 7.6 feet deep, there were too many “fish marks” on the screen to count.

With more than 100 species of fish swimming in this river, most fish marks were probably species other than walleyes. No matter. The first step in catching fish is finding fish.

Seven of the nine fish landed over the next three hours hit the Rapala with the busted lip and missing treble hook.

Two lures and a walleye flopping in a landing net is a guaranteed recipe for a tangle. This is why there are two landing nets in the boat. Twice we had to use the anchor feature on the trolling motor in a time out to untangle nets.

Both intermissions brought smiles without complaint. Complaints were reserved for the wind. Fishing in gusts to 30 mph is never fun.

But its more fun than sitting at home.

Ted Peck, a certified Merchant Marine captain, is an outdoors columnist for The Gazette. Email him at tedpeck@acegroup.cc.